Fumigating system



Patented June 21, 1949 U fN [TED iJS T fQFFl'llCSE FUMIGATING 'SYSTEM fArthur G. Howard,` Flint; Mich.

Application June3.,-1946.Serial No. 673,999

(Cl. 21d-108i 'The invention relates to improvements .in a system'for'fumi`ga'ting, and more particularly to an arrangement whereby'aninsecticidalgas may be deliveredinto various/equipment requiringfumig'ationat stated intervals andior predetermined periods of time.

`The'system embodying. the features of 'the .present 'invention"islintendedl for 'use ,primarily in connection'With'the'iumiga'tion ofvarious types of l:millingv equipment, 'suchas elevators, reels,puriers,1grinding rolls; .packing and .storage'bins and'other""our ord'ough`handling equipment. The system involves an organization includinga source for generating 'an insee'ticidal 'gas-'from liquid. insecticideor'fumi'gant and yasuit'able system 'of piping y"for "conveying thegas'. to' various pieces of" milling 'equipment located in differentsections and .on diierentfloo'r levels of .a building"housin'g "suchequipment. 'Fumigation 'of milling 'equipment 'in particular I is'effected a't regularly spaced intervalsv vsuchY asl .at Weekly orbis'monthly" periods .i primarily to 'destroy insects and incidentlyto`eliminate the actionfo'f-lmolc'l spores :prevalent in 'our and doughhandling machinery. Y

It is; therefore, an 'obj ect 'of :thejpresent invent'ionfto provide rasystemior iumi'gation, `which iis easy t0 installinnew orexis'tingmillsand which is highly efficient in use tand entirelyautomatio inv itsoperation.

VThe -furnigation vof equipment 'distributed throughout variouspa'rtsofa'building 'through the #operation 'of-"fa Mcentrally 'arranged"furnigat apparatus has heretofore been inadvisable @because of thediculties involved in 'regulating the flow of inseoticidalgas to theindividua'lpieces of equipment, and-because 0i the I"difficultiessurrounding lthef-"dis'tribullion `of 'sa'd' 'gas Ito selected pieces ofsuch equipment. Aiills a result, "it has 'been common practice vtoseparately funriigate 'ea'ch pieceoffequipmentat selected intervals.4However, because v"of the uncertainty 'surrounding such practice,fit1is"pr'eferred to vvprovide-a"single apparatus v4ope1'able in'responseto automatically actuatedY timedc'ontrol idevices'eiecti-ve *toen'ab'rl'e f-uxngation offfallv'of *the1-feeu`ipinent4v during=operation of .said apparatus; and 'infsu'chfmanner as to yvi'nsureproper yffumiga'tionl y:of `reach" piece Iof equipment-.- connected iny.tl-re system. Etuis; thereforesanother objectrof the'inyentonxtoprovidea system. ofI fumigfa'tion 'whiche'mhocii'es1 all'- :of l'lthedesirable charaeteristicsfeofzzthe systemziresp'onding to' that referredtof hereinabove.

)Qtherand lfurther :objects sof Ithe*presentiiinvention willbeapparent-fromnthe.following de` f scriptionand claims and areillustrated 1in""the accompanying draw'rjig Which,by Way of:illustration, 'shows apreferred embodiment andthe principle'thereof.'Other embodiments of 'thefinventi'on 'embodying the same lprinciplemay'fbe used and' structural changes may be" madeasdes'iredby thoseskilled intheart Without depart ingiromthe present "invention andapurview 'f the appended claims.

The flgure'isaschematie view 'showing 'abuil'ding in section .andprovided at'various'fl'oor levels with different 'types 'o'f .'imillingequiprnent `commonly used 'for 'handling flour,l dough, 'or the'like;and 'showing the improved system.' offfumigatin incorporated therein.

The 'system 'of Vfumigation'illustrated ,in the drawn-1gIisrepresentative of 'an installation organ-izedto,ipermitfiuniigation'of 'a considerable number of "pieces `o'i,oliierent"kinds of 'equipmentfound in the milling and baking imdustry, 'and it 4includes"a1-"singleapparatus 'forigeneratingin` secticidal Jgasv and automatic' timecontrol .means actuable to 'placevarious' sections of'ithe system'indirect `commu-n'ication Witl'i "theappara'tus during certain periods ofapparatus operation so a'sto thereby cause variousr groups tor pieces'of equipment to lbev-fumigatedin succession. "This 'system permits i'av''singlegenerating "apparatus oi 'moderates'izeory 'cost-"to serve anentire plant, and also favoids `the' 'need Y for `rone "or more portablegenerators movable into close "association `yvi'th each'- r'piece ofmilll'ing Aequip'n'ient for fumiga'ting that piece of *equipmentindependently A'of all others.

' 4Inpracticingthepr'e'sent" inventioma building housingv the milling`or yother `equipment Ito' be fumigatedfissuitablypiped 'soas to enabledistribution of thejinsectioidal lgas toeach piece df equipmentrequiring Vsuch iumigation r-irrespective of the` location of suchequipment. An e'xample l'of su'chv4 an vinstallation vis disclosed inthedrawing'whereinfthe 'building illustrated has a paratus, indicatedgenerally at I6, for generating insecticida1 gas from a liquidinsecticide and which may be of a kind shown and claimed in my copendingapplication Ser. No. 674,000, led June 3, 1946, is arranged on thelowermost licor level and a standpipe I'I extends from said apparatusupwardly through the various iioor levels to adjacent the ceiling of theuppermost floor level. The standpipe may, of course, include branches orextensions leading to other sections of the building and containingequipment other than that illustrated in the drawing, which branches orextensions are not necessary to a complete disclosure of the inventiondescribed herein.

A plurality of distribution lines, I8, I9, 2I, and 22, are connectedinto the standpipe I'I' to receive fumigant gas flowing through thestandpipe during certain periods of generator operation. Thedistribution lines normally are shut oli from the fumigant gas containedwithin the standpipe I'I so that any condensate that may accumulatetherein will ow in the direction of said standpipe. To facilitate thedrainage of condensate from each of the distribution lines I8 through22, inclusive, said lines are each provided with a bleed conduit 2'Ihaving a checkvalve 28 therein to prevent the flow of insecti cidal gastherethrough. The check-valves, however, permit condensate to ow fromthe respective distribution lines into the standpipe I'I when thegenerating apparatus I6 is not in operation.

Each of the distribution lines I8 through 22, inclusive, is providedwith a plurality of outlets each having a conduit 29 connected thereto.The conduits 29 may extend upwardly through the respective oor levelsII, or downwardly if the distribution line is adjacent the ceiling, andare provided at their discharge ends with dispensing valves 3|communicating with the interior of the selected piece of millingequipment with which it is associated. Thus, each piece of millingequipment I2, I3, I4 or I5, is directly connected with one of thedistribution lines I8 through 22, inclusive, by means of one of theconduits 2S.

A time control unit 32 is connected in the electrical circuit to thegenerating apparatus I6 which unit may be of any conventionalconstruction embodying switch mechanisms adapted to hold selectedcircuits closed for predetermined periods of time and capable of beingmanually or automatically actuated to initiate operation of the system.The time control unit 32 is connected electrically to each of thesolenoid valves 23, 24, 25, and 26, and is so constructed that when inoperation it will successively open and then close the solenoid valves.In the present installation, starting of the time control unit manually,or in response to clock control mechanism, initiates operation of thegenerator apparatus I6 and also opens the solenoid valve 26 provided inthe distribution line 22. The solenoid valve 26 will remain open for atime interval depending upon the setting of the control unit, duringwhich interval insecticida1 gas generated in the apparatus I6 anddelivered under pressure into the standpipe I! will iiow into thedistribution line 22 and its conduits 29 for discharge into the interiorof the reels I2.

It has been found that a period of operation approximating one hour issufcient to deliver the required amount of insecticida1 gas to the reelsI2 for combating insect growth therein. At the conclusion of this orother predetermined period of operation, the time control unit 32operates to open the valve 25 in the distribution line 2I and close thesolenoid valve 26 in the distribution line 22. Insecticidal gas iiowingthrough the standpipe I1 then is delivered into said line 2I and throughthe conduits 29 connected therewith for discharge into the purifiers I3.After a suiiicient quantity of insecticida1 gas has been delivered tothe purifiers I3, the time control unit 32 again operates to open thesolenoid valve 24 in the distribution line I9 and close the solenoidvalve 25, whereupon insecticida1 gas is delivered to the grinding rolls`I4. When the fumigation of the grinding rolls is completed, the timecontrol unit 32 again operates to open the valve 23 in the distributionline I8 for delivering insecticida1 gas into the storage bins I5, atwhich time the solenoid valve 24 is closed. At the conclusion of theoperating period necessary to fumigate the storage bins I5 the timecontrol unit again operates to shut down the generating apparatus I 6and then close the valve 23. v

It should be quite evident from the foregoing description that all ofthe equipment in a mill requiring treatment with insecticida1 gas atpredetermined intervals is fumigated through the operation of a singlegenerating unit by means of the present system of fumigation. In thismanner, a single unit may accommodate a large number of pieces ofequipment, some of which are treated for a required period of timebefore other pieces of equipment are successively cut into the systemfor treatment, and that any condensate accumulating in the distributionlines I8 through 22, inclusive, will return to the standpipe I'I and tothe generating apparatus I6 following shut down of the system.

It should be understood further that although an exemplary installationhas been disclosed in the accompanying drawing and described in detailin the foregoing specification, the system may include other andadditional equipment than that shown, and may be installed in buildingshaving such equipment located on different floor levels or upon a singlefloor level. In the latter instance, various pieces or groups ofequipment will be independently piped through main distribution linesfrom the standpipe I'I or other header, and each of such lines will havean electrically controlled valve therein electrically connected with thetime control unit so that said valves may be opened and closed insuccession to thereby avoid overloading the generating apparatus I6.

I claim:

vl. In a system for fumlgatlng which comprises an apparatus forgenerating insecticida1 gas, a standpipe through which said insecticida1gas is delivered, a plurality of distribution lines connected into saidstandpipe, a normally closed valve in each distribution line, and meansactuable to initiate operation of the generating apparatus and to openand close said valves in succession so as to successively place eachdistribution line in communication with the standpipe for predeterminedperiods of time.

2. In a system for fumigating which comprises an apparatus forgenerating insecticida1 gas, a standpipe through which said insecticida1gas is delivered, a plurality of distribution lines connected into saidstandpipe, a normally closed valve in each distribution line, meansactuable to initiate operation of the generating apparatus and to openand close said valves in succession so as to successively place eachdistribution line in communication with the standpipe for predeterminedperiods of time, and a by-pass in each distribution line eiective tobleed said line when the generating apparatus is shut down.

3. In a system for fumigating which comprises an apparatus forgenerating insecticidal gas, a standpipe through which said insecticidalgas is delivered, a plurality of distribution lines connected into saidstandpipe, a normally closed Valve in each distribution line, meansactuable to initiate operation of the generating apparatus and to openand close said valves in succession so as to successively place eachdistribution line in communication with the standpipe for predeterminedperiods of time, and a by-pass in each distribution line eiective tobleed said line when the generating apparatus is shut down, said meansbeing effective to shut down the generating apparatus when the lastdistribution line valve is closed.

4. In combination with a building structure having a plurality of iioorlevels and equipment to be fumigated on each level, a generator for aninsecticidal gas located on a lower oor level of such structure, astandpipe extending from said apparatus, distribution linescommunicating with said standpipe one at each floor level, and aplurality of conduits connecting each distribution line with equipmentlocated on said level.

5. In combination with a building structure having a plurality of oorlevels and equipment to be fumigated on each level, a generator for aninsecticidal gas located on a lower oor level of such structure, astandpipe extending from said apparatus, distribution linescommunicating With said standpipe one at each iioor, a plurality ofconduits connecting each distribution line With equipment located onsaid level, and a dispensing valve in each of said conduits.

6. In combination with a building structure having a plurality of floorlevels and equipment to be fumigated on each level, a. generator for aninsecticidal gas located on a lower floor level of such structure, astandpipe extending from said apparatus, distribution linescommunicating with said standpipe one at each iioor level, meansoperable to initiate operation of the generator, said means beingeffective to place said distribution lines in communication with thestandpipe during apparatus operation and to shut down the apparatusafter a predetermined period of operation, and a plurality of conduitsconnecting each distribution line with equipment located on said level.

7. A system for fumigating which comprises a source of fumigant gas, astandpipe through which said fumigant gas may ow, a plurality ofdistribution lines connected into said standpipe, a normally closedsolenoid valve in each distribution line, means opera-ble to actuatesaid valves in timed sequence so as to successively open and after apredetermined time close said valves, conduits connecting saiddistribution lines with the equipment to be fumigated, and dispensingvalves in said conduits.

8. A system for fumigating which comprises an apparatus for generatingfumigant gas, a standpipe through which said fumigant gas may ow, aplurality of distribution lines connected into said standpipe, anormally closed solenoid valve in each distribution line, means operableto actuate said valves in timed sequence so as to successively open andafter a predetermined time close said valves, and conduits connectingsaid :distribution lines with the equipement to be fumigated.

9. In a system for fumigating which comprises an apparatus forgenerating insecticidal gas, a standpipe through which said insecticidalgas may be delivered, a plurality of -distribution lines connected intosaid standpipe, a normally closed valve in each distribution line, meansactuable to initiate operation of the generating apparatus and to openand close said valves in succession so as to successively place eachdistribution line in communication with the standpipe for predeterminedperiods of time, and means by-passing each valve effective to enablecondensate in each distribution line to ow into the standpipe when thevalve is closed and the generating apparatus is shui-l down.

ARTHUR. G. HOWARD.

No references cited.

